Fong Vang wrote:
> (or why the system does not release the semaphore if Apache
> is no longer running).
Because IPC resources (semaphores, message queues and shared memory
segments) are not tied to a process, an process simply has access to
them (and can request for resource to be created or destroyed). It is
perfectly OK for a process to create any IPC resource, exit, and then
some other process started at a later time to pick it up. If something
is allocating IPC resources and not cleaning up behind itself, than it
is a bug in application (where application != process). IPCs are
outside of that nice box called process, so you should think outside of
the box too.